masters of gl, please step forward...
i work with three layers of grayscale live video all rendered into the same window, some with alpha.
before rendering, i need to adjust brightness and contrast (same for all layers) which i do via jit.gl.slab and the cc.brightness/contrast.ip.jxs shaders.
now, this works well until i aply this to a video with alpha - if i do, the alpha is not transparent any more but displayed as solid grey.
if i bypass the two jit.gl.slabs, it works as it should. did i do anything wrong or do these shaders simply not support alpha?
(and what would i do then?)
if you look at the patch attached, the middle one is the problem.
apart i am wondering if there is a neater way to program this anyway... currently, i use six slabs for basically just adjusting brightness and contrast which does seem somewhat excessive...